Portable hand tools having torque responsive clutches which are coupled to a driven output member are well-known in the art. One such example is shown in U.S. Pat. No. 3,766,990 issued Oct. 23, 1973 to Eckman, et al. In the design shown in the patent a rotatable spindle, which is adapted to be interconnected with a driven output member, is in turn driven by a drive member through a torque responsive clutch. In Eckman, et al. a clutch carrier is secured to his output spindle, the clutch carrier supporting a plurality of clutch balls which engage a cam member having a plurality of spaced apart recesses. A compression spring normally biases the clutch balls into the recesses of the cam member but when an overload torque condition is encountered by the driven output member, the clutch balls will be cammed out of the recesses. In the design shown in the patent and in other well-known commercial variations of this form of torque responsive clutch it is necessary to provide thrust bearings of various forms which receive the thrust forces exerted by the spring, the thrust bearings transmitting the thrust forces either to the spindle in the manner shown in the Eckman, et al. patent or to a cylindrical housing disposed about the rotatable spindle in the manner shown in the U.S. Pat. No. 3,020,789 issued Feb. 13, 1964 to Etzkorn, the thrust bearing being indicated at 26 in this particular patent.
The foregoing designs are relatively difficult to assemble, and also are somewhat more costly than the design shown in this application in that they require thrust bearings.